Update a result vector when sampling animation effects.

Source/core/animation/AnimationStack.cpp

Index: Source/core/animation/AnimationStack.cpp
diff --git a/Source/core/animation/AnimationStack.cpp b/Source/core/animation/AnimationStack.cpp
index dab12deb04b150e02c3a292f4e1dba88fd4978c3..aabdc8327884da54606fbc64b310951358e0c50d 100644
--- a/Source/core/animation/AnimationStack.cpp
+++ b/Source/core/animation/AnimationStack.cpp
@@ -59,10 +59,10 @@ bool compareEffects(const OwnPtrWillBeMember<SampledEffect>& effect1, const OwnP
 void copyNewAnimationsToActiveInterpolationMap(const WillBeHeapVector<RawPtrWillBeMember<InertAnimation> >& newAnimations, WillBeHeapHashMap<CSSPropertyID, RefPtrWillBeMember<Interpolation> >& result)
 {
     for (size_t i = 0; i < newAnimations.size(); ++i) {
-        OwnPtrWillBeRawPtr<WillBeHeapVector<RefPtrWillBeMember<Interpolation> > > sample = newAnimations[i]->sample(0);
-        if (sample) {
+        OwnPtrWillBeRawPtr<WillBeHeapVector<RefPtrWillBeMember<Interpolation>>> sample = nullptr;
+        newAnimations[i]->sample(0, sample);
+        if (sample)
             copyToActiveInterpolationMap(*sample, result);
-        }
     }
 }